Evaluating the Role of Ultrasonication‐Assisted Alkali Pretreatment and Enzymatic Hydrolysis on Cellwall Polysaccharides of Pennisetum Grass Varieties as Potential Biofuel Feedstock

Abstract

Production of renewable fuel like bioethanol from plant biomass and agro wastes will be the future energy source to combat the depletion of fossil fuels. The first detailed profile of the non‐cellulosic cell wall polysaccharides of native, ultrasonication assisted alkaline (NaOH) pre‐treated and enzyme hydrolysed Pennesitum grass varieties viz. hybrid Napier grass and denanath grass, were identified using glycome profiling. The best pre‐treatment conditions resulted in 89.3% and 86.7% delignification of denanath grass (DG) and hybrid Napier grass (HNG) respectively. In the same conditions, 227.2 mg/g and 242.8 mg/g of total reducing sugar was achieved for DG and HNG respectively. Comparative assessment of a new enzyme i. e. Palkonal MBW with the conventional combination of Celluclast 1.5 L+ xylanase was undertaken. The amounts of glucose and xylose released with Palkonal MBW saccharified DG and HNG were 662.0 mg/g and 431.2 mg/g, which were significantly higher as compared to the conventional enzyme cocktail. The glycome profiling results showed that pectic arabinoxylan and arabinogalactan backbones were significantly less in DG samples and they do play a major role in enhancing enzymatic hydrolysis. These reports can provide a good insight in designing potential perennial feedstocks for bioethanol production in bio refinery concepts. Furthermore, the underutilised DG variety may also be exploited owing to its promising cell wall characteristics that can produce higher bioethanol yields.

Intensification of alkaline delignification of sugarcane bagasse using ultrasound assisted approach

“…Similar trend was reported by Subhedar and Gogate [13] who observed that duty cycle till optimum increment causes increment in delignification with maximum delignification of 70.92 % elucidated at 70% duty cycle. Mohapatra et al [44] also reported that increment in duty cycle and time resulted in higher yields only till an optimum condition of 50% duty cycle and 30 min as the time with maximum yield as 135.8 mg/g for denanath grass as the substrate.…”

Ultrasonic Irradiation Enables Facile Production of Lovastatin from Sugar Cane Bagasse

“…This may be due to increased effects of cavitation that enhanced the rates of reactions. 26 The sonication time required depends on the amplitude. The mutual interaction between amplitude ( X 2 ) and sonication time ( X 4 ) was found to be significant, as the model Prob > F is less than 0.05, as shown in Figure 2 e. The pretreatment time for SCB was shortened from 60 to 45 min by increasing the amplitude from 68.4 to 102.6 μm for high lovastatin production (1705–2295 μg/g).…”

“…In the case of sonication time, as shown in Figure c,e,f, lovastatin production increased with an increase in sonication time to 60 min. This may be due to increased effects of cavitation that enhanced the rates of reactions . The sonication time required depends on the amplitude.…”

Life cycle assessment of bioethanol production from Pennisetum sp. using fed‐batch simultaneous saccharification and cofermentation at high solid loadings

“…Pretreatment of DG and HNG was conducted using ultrasonication-assisted NaOH (UA-NaOH) conditions as previously described in Mohapatra et al 28 The pretreated DG and HNG biomass were further saccharified with the most suitable parameters using two different sets of enzymes. In the first set, the combination of two commercial enzymes, that is, Palkonal MBW (a mixture of cellulase-12 000 Maps cellulase unit (MCU)/mL and hemicellulose-5000 MHCU/ mL, 28 was considered. The second set of enzymes consisted of an isolated cellulase (IC) + commercial xylanase (Xyl) (enzyme activity of the IC was 1.35 U/ mL and 8450 U/mL for Xyl enzyme).…”